[NFC][Codegen] Use MaybeAlign + APInt::getLimitedValue() when creating Alignment attr

[lebedev.ri]

Summary

Just an NFC code cleanup i stumbled upon when stumbling through clang alignment attribute handling.

[gchatelet]

Thx!

[lebedev.ri]

In D72993#1828934, @gchatelet wrote:

Thx!

Thank you for the review!

clang/lib/CodeGen/CGCall.cpp

case ABIArgInfo::Direct: {
           if (AVAttr && !SanOpts.has(SanitizerKind::Alignment)) {
             // If alignment-assumption sanitizer is enabled, we do *not* add
             // alignment attribute here, but emit normal alignment assumption,
             // so the UBSAN check could function.
             llvm::Value *AlignmentValue =
               EmitScalarExpr(AVAttr->getAlignment());
             llvm::ConstantInt *AlignmentCI =
               cast<llvm::ConstantInt>(AlignmentValue);
-            unsigned Alignment = std::min((unsigned)AlignmentCI->getZExtValue(),
-                                          +llvm::Value::MaximumAlignment);
-            AI->addAttrs(llvm::AttrBuilder().addAlignmentAttr(Alignment));
+            AI->addAttrs(llvm::AttrBuilder().addAlignmentAttr(llvm::MaybeAlign(
+                AlignmentCI->getLimitedValue(llvm::Value::MaximumAlignment))));
           }
         }
 
         if (Arg->getType().isRestrictQualified())
           AI->addAttr(llvm::Attribute::NoAlias);
 
         // LLVM expects swifterror parameters to be used in very restricted
         // ways.  Copy the value into a less-restricted temporary.